Cerberus is totally the best kind of dog; multiple heads for petting, but only one butt for pooping.*

That is, of course, assuming it’s not one of those drooly dogs, with the drooling and the mouth froth. Then you’ve got three times the spittle, as well. BUT ONLY 1 BUTT FOR POOPING. It’s still a win.
*I was going to make some sort of convoluted comment about how Cerberus guards the river Styx, and how the only Styx song I know is Sailing Away, and how intensely awesomely ridiculous that song is, but I though a poop joke was funnier. We like to keep it classy here at Robot a Day.